How to Recover Refrigerant From an HVAC System

Identify the type of refrigerant used in your HVAC system. Determine how much refrigerant is in your system or the part of the system on which you're working. When reusing refrigerant, use a tank that holds the same type of refrigerant to prevent mixing different types.

Purchase or rent a refrigerant recovery machine that includes connections, control, pressure gauges, a compressor, motor and condenser. Pressure gauges monitor the pressure in the refrigerant tank and your rate of progress during the recovery procedure.

Familiarize yourself with the equipment and identify ports for recovery that are based on your HVAC system's pumping down instructions.

Choose hoses that reduce refrigerant friction flow and facilitate fast recovery. Use common 3/8-inch lines for input to the refrigerant recovery machine and as short a hose as possible.

Remove Schrader valve and core depressors before starting the recovery process with an adjustable wrench. Inspect O-rings at each end of the hoses to ensure proper sealing.

Attach a hose on both ends of the recovery machine at the discharge side. Connect other end of the hose to the tank liquid port of the cylinder you're using to recover the refrigerant.

Connect a hose from the bottom servicing port of the HVAC system to the charging port of the manifold. Connect another hose from the lower side of the manifold to the suctioning side of the refrigerant recovery machine or equipment.

The hose in the middle of the manifold connects to a particulate or drier filter. The drier filter prevents gunk from getting into the recovery machine. The hose attaches to the liquid port on the recovery cylinder.

Connect a hose from your tank vapor port to a gauge on the manifold so you can check tank pressure.

Close the valves on the manifold. Open the liquid and vapor valves of the cylinder or tank. Switch on the machine to start the recovery process. Suction pressure should hold steady at 2 to 5 pounds pressure.

Operate the refrigerant recovery machine until the gauge on the manifold shows vapor vacuum. Turn the machine off, closing the manifold and intake port valves.

Watch the gauge pressure, which should now read below zero. If it doesn't, repeat the process.

Flip the switch on the refrigerant recovery machine to purge. Follow the directions offered by HVAC system manufacturer according to model and size.

Complete the process by closing the valve on the recovery tank. Disconnect your hoses and return the valves and caps into place on the HVAC unit.